Allegheny County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Allegheny County: 2.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Mapped landslides

Mapped by USGS PA (Pomeroy, 1974) (7,232), NASA (98), USGS Conterminous (1).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Jun 30, 1998Thunderstorm Wind$41.0 million
   National Weather Service narrative

   A microburst with winds up to 85 MPH moved diagonally from northwest to southeast across Allegheny County, leaving a wide swath of damage in its wake. These winds produced an estimated $41 million in damage across the county. Over 125,000 people across the county had their power knocked out by this storm. Across the city of Pittsburgh, the North Hills area reported numerous trees, branches, and power lines down across an area one to two miles wide and nearly five miles in length. Many homes were damaged by falling trees and branches. The Larouche College area was especially hard hit with significant roof and window damage. The roof was torn from a McCandless convent, injuring three nuns.

2. Sep 17, 2004Flood, Allegheny$26.0 million
   National Weather Service narrative

   At 124 PM EDT on 17th, road flooding was reported 2 miles west of Pittsburgh. At 2 PM, Wexford flooded. At 218 PM, roads flooded in Oakdale. By 315 PM, Springdale Boro flooded; and Wexford had 4.5" of rain. . By 450 PM on 17th, in Tarentum, Mill St and Davidson St were flooded; people evacuated. By 5 PM EDT on 17th, a state of emergency was declared in 62 of the 130 municipalities of Allegheny Co. South Park 6" of rain 530 PM EDT 17th. At 6 PM, evacuations in Tarentum. Widespread flooding stranded thousands. A total of 9494 homes, 1060 businesses, 4 schools, 9 fire depts, 50 public buildings damaged or destroyed. 140 boats broke away and ran away down several rivers. Some towns…

3. Aug 9, 2007Flash Flood$15.0 million
   National Weather Service narrative

   Heavy rain caused flash flooding in the Millvale area and much of the North Hills area of Pittsburgh as Girtys Run came out of it's banks. Over 900 homes were affected by the flooding as well as over 200 businesses. Infrasturcture owned by local municipalities sustained over 4 million dollars in damage.

4. Jun 2, 1998Tornado$13.0 million
   National Weather Service narrative

   An F1 tornado touched down 5 miles northwest of Carnegie in Allegheny County and moved east-southeast across the southern and eastern suburbs of Pittsburgh into Westmoreland County. The total path length of this tornado was estimated to be 32 miles, and damage was reported in Mount Washington, Hazelwood, and Rankin in Allegheny County. As the tornado passed over a concrete railroad overpass about 2 miles north of Baldwin, it blew several railroad cars onto their sides. The tornado continued into Westmoreland county, moving through the towns of Irwin and Manor. The Mount Washington area, located just south of downtown Pittsburgh, sustained the majority of damage, along with all of…

5. May 31, 2002Thunderstorm Wind$10.0 million
   National Weather Service narrative

   A macroburst roared across eastern Allegheny and extreme western Westmoreland counties during the early evening hours of May 31st. This macroburst produced an approximately 10-mile long path of damage from the straight-line winds, which were estimated as high as 105 MPH. The macroburst damage path originated in the Homestead area of eastern Allegheny County, with the outflow winds traveling to the southeast through the towns of Whitaker, West Mifflin and Duquesne. The macroburst outflow then continued across the Monongahela River into the towns of McKeesport and North Versailles. Outflow winds from this macroburst continued to the southeast, weakening as it crossed into…

6. Aug 6, 2000Flash Flood$10.0 million
   National Weather Service narrative

   Widespread flash flooding problems were reported across the county, with 51 of the county's 130 municipalities reporting some degree of storm impact. Of those 51 municipalities, 15 reported significant impact, including flooding of streets and basements, washed-away property and cars, and roadway infrastructure damage. An estimated 1200 homes and businesses in those 51 communities were impacted. The Allegheny County Chief Executive's office reported the hardest-hit communities were Baldwin, Brentwood, Hays, Mt. Lebanon, West Mifflin, and the City of Pittsburgh along the Route 51/88 corridor. The town of Hays was probably the hardest hit of all the communities, with over 75 homes…

7. Jun 20, 2018Flash Flood$10.0 million
   National Weather Service narrative

   The 911 Call Center has reported that a number of roads in southern Bethel Park have been flooded and/or impassable. This roads include: Glendale Drive, Logan Road, O'Neill Drive, Dashwood Drive (vehicle was stuck in water). Water entered the Trolley Stop Inn restaurant, cars in the parking lot were submerged (some floating); customers had to be rescued from the building. Local newspaper reports say at least 400 homes have been damaged and two homes were damaged so severely that they became uninhabitable. There was 1 direct injury; a young man was sucked into a storm drain while helping others trapped in the flood. He received a few bruises for this incident.

8. Jul 1, 1997Flash Flood$10.0 million
   National Weather Service narrative

   A nearly stationary thunderstorm formed over the eastern part of Allegheny County during the evening of July 1. The storm dropped near 4 inches of rain in about 90 minutes over a 4 square-mile area. The resulting flash flood was centered in a small watershed in and near Pitcairn. Radar estimated rainfall rates greater than 2 inches per hour for almost 40 minutes. A rain gage at the Gateway Middle School indicated 3.30 inches storm total. Most of the damage was along Dirty Camp Run and Abers Creek. The town of Pitcairn was particularly hard hit. The streambed of Dirty Camp Run, a tributary of Turtle Creek, flows through the heart of the urbanized area of Pitcairn, where the channel…

9. Jun 19, 1996Flash Flood$3.0 million
   National Weather Service narrative

   Heavy thunderstorm rains continued to create flash flooding conditions throughout the county. Some roads, including Allegheny River Boulevard in downtown Pittsburgh, experienced extensive flooding.The most significant flash flood event occurred at an automobile dealership in southeast Allegheny County between 6 and 7 am EST. Long Run and Jack's Run went out of their banks. Homes were flooded along Route 48. Flooding along Long Run swept 3 vehicles into a large storm water catch basin. The first auto was a compact and was later discovered over a mile downstream from the dealership. The other two vehicles were larger sport-utility vehicles and they became lodged in the culvert. Of…

10. Oct 6, 2024Thunderstorm Wind$2.0 million
    National Weather Service narrative

    Babcock Boulevard in Shaler Township was closed due to downed trees and powerlines.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

102°FJul 14, 1936

All-time low

−16°FJan 23, 1936

Warmest night

77°FAug 12, 2016

Coldest day

−2°FJan 23, 1936

Wettest day

6.00 inSep 17, 2004

Snowiest day

12.0 inNov 24, 1950

Hottest year

2024mean 56.6°F

Coldest year

2003mean 51.0°F

Wettest year

201866.71 in

Driest year

194629.24 in

Station Pittsburgh Allegheny County Airport (USW00014762), 1,244 ft elevation, 6.9 miles from the population centre. Daily records from 1935 to October 26, 2026; 91.8% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USW00014762.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.